One-piece oil pump



Aug. 6, 1 963 R. A. HARRIS ETAL 3,100,027

ONE-PIECE on. PUMP Filed Oct. 12, 1960 INVENTORS ATTORNEY United States Patent 3,100,927 ONE-PECE 01L PUMP Richard A. Harris, High Point, and Carroll D. Spainhour, Greensboro, N.C., assignors to Western Electric Company, Incorporated, a corporation of New York Fiied Oct. 12, 1960, Ser. No. 62,294 2 Claims. ((31. 184--6) This invention relates to an apparatus for pumping fluid and more particularly to a one piece centrifugal oil pump for pumping a lubricant from a reservoir and for distributing the lubricant over the working surface of a gear.

In the past, oil pumps used in high speed gear trains have used systems such as impellers, vanes, and the like in order to lift a lubricant from a reservoir and distribute the lubricant upon the gear train. The vanes or impellers utilized in these old systems have a tendency to agitate the lubricating oil and create foam in the reservoir. This foam is often drawn into the pump and interferes with suitable distribution of the lubricating oil and can result in damage to the working parts being lubricated. Since the instant apparatus uses no vanes, impellers, or the like for lifting the fluid, but simply utilizes centrifugal forces acting on a rotating body of fluid little or no foam is produced in the oil reservoir by the rotating pump and, consequently, the problem of foam is overcome. Additionally, the prior art utilizes pumps which are composed of several moving or connected parts. Since many of these pumps are used at high speeds, the interconnected or moving par-ts have a tendency to wear, thus reducing the mechanical reliaability of the pump. The instant invention overcomes this problem because it is a one piece unit having no interconnected parts. The fact that it is a one piece unit adds to its durabilty and reliability of use.

It is an object of the present invention to provide a new and improved oil pump.

It is another object of the invention to provide a one piece oil pump for lubricating a gear train.

It is still a further object of this invention to provide a one piece oil pump forming an integral part of a gear in a gear train for lubricating the gears of the gear train.

It is still a further object of this invention to provide a one piece oil pump utilizing a centrifugal force acting on the lubricant for lifting the lubricant from a reservoir and distributing it over a surface to be lubricated.

It is still a further object of the present invention to provide a new and improved oil pump utilizing centrifugal forces acting on a moving body of liquid to create a pressurized reservoir of liquid in a cavity within the pump. The pressure head developed forces the liquid over a surface of working parts to be lubricated.

With these and other objects in view, the present invention contemplates the use of a gear having a pump as an integral part thereof. The pump has a main body with an extension enclosing a frustu-m-like cavity with an intake opening. The intake opening is submerged in a reservoir of fluid and the entire pump assembly, including the pump and gear are rotated at relatively high speeds. Fluid is drawn into the cavity of the pump Where the fluid is en trapped to create a pressure head. The developed pressure then forces the fluid upwardly through passageways in the body of the pump to a discharge opening. Since the gear and discharge openings are rotating at relatively high speeds, the discharged fluid is dispensed radially and lubricates a gear which is meshing with the pump gear.

Other objects and advantages of the invention will become apparent by reference to the following detailed description when considered in conjunction with the laccompanying drawings wherein:

FIG. 1 is a view of a gear train utilizing a one piece oil pump, which pump is shown in section and illustrates the "Ice structure which encompasses the principles of the present invention;

FIG. 2 is a bottom view of FIG. 1 showing a one piece oil pump and gear meshing with a second gear which is to be lubricated;

FIG. 3 is a fragmentary section of a portion of a one piece oil pump as illustrated in FIG. 1 and shows the force components which are acting on lubricant or other fluid which is being pumped into a reservoir cavity; and

FIG. 4 is a section view of a modification of the one piece oil pump illustrated in FIG. 1 showing oil passageways which are not parallel to the axis of the pump and showing a pump having a reservoir cavity of a modified shape.

Referring to FIG. 1 there is shown a gear train utilizing a one piece oil pump, generally designated by reference numeral 11 which is utilized to lubricate \a spur gear 12. A drive motor 14 drives a gear train 13 consisting of a gear 15 and a gear 16 to rotate pump 11 at relatively high speeds. An intake opening 17 which lies in a minor surface of pump 11 is submerged in a lubricating fluid reser voir 18 and fluid is forced into cavity 19 to a portion of the cavity to form a pressure reservoir 21. A pressure head is developed in pressure reservoir 21 due to the fluid 22 being forced along the smooth, conical Walls 23 of the pump 11. Since there is a pressure head existing within cavity 19, lubricating fluid is forced through passageways 24 to discharge openings 25. The high speed rotation of pump 11 dispenses fluid flowing from discharge opening 25 in a radial direction and dispensed liquid 26 is deposited on spur gear 12, thus lubricating the surface where gears 12 and 27 mesh. The fluid actually sprays from the openings 25 in the form of a mist.

Motor 14 rotates a gear 27 and pump 11 mounted on hearing 46, at relatively high speeds in contact with fluid in reservoir 18. The fluid immediately adjacent the intake opening 17 and fluid which is Within the intake opening 17 is set in motion by the rotation of pump 11. This fluid is set in motion by the friction which exists between the conical wall 23 and the body of fluid 18. Since the pump '11 is rotating, the fluid immediately adjacent the intake is rotated in a circular path. This circular rotation creates centrifugal forces which act upon the fluid and tends to force the fluid in a radial outward direction from pump axis 28 in FIG. 1. These radial forces which act on the rotating fluid are illustrated by force vector 29 of FIG. 3. Force vector 29 can be resolved into two vector components 31 and 32. Vector component 31 is normal to wall 23 and tends to hold liquid 22 against wall 23 while pump 11 is rotating. The second and most important vector component 32 :of vector 29' is a force which is parallel to wall 23 and which is directed upwardly along wall 23. Vector component 32 represents the force which lifts the rotating fluid into cavity 19 and forces the fluid into pressure reservoir 21 where conical wall 23 intersects wall 33 which forms a major enclosing surface on the cavity '19 of body 34.

It should be particularly noted that conical wall 23 contains no vanes or irregularities for conveying fluid 22 upwardly to reservoir 21. The fluid is lifted entirely as a result of the afore-described centrifugal forces acting on the fluid. The absence of vanes reduces agitation of the fluid in reservoir 18 and effectively prevents the formation of foam. Force vector component 32 is of considerable magnitude and forces fluid 22 upwardly along wall 23 with enough force that a pressure head is created in reservoir 21 within the cavity 19. Passageways 24 in body 34 connect pressure reservoir 21 with discharge openings 25. The pressure head created within pressure reservoir 21 forces the fluid in pressure reservoir 21 upwardly through passageways 24 to discharge opening 25. Since pump 11 and gear 27 are rotating at relatively high speeds, fluid 26 dispensed from discharge openings 25 is dispensed radially due to the action of centrifugal forces. The fluid 26 is actually sprayed from discharge opening 25 over the surface 35 of spur gear 12. The sprayed fluidor lubricant is of adequate quantity to properly lubricate the meshed working surfaces of gears 12 and 27 as determined by the speed of rotation of the pump and by the size of the passageways 24. Excess lubricant drains from the lubricated surfaces of gears 12 and 27 and returns to the fluid reservoir 18 to be recirculated through the system.

Due to the rotation of pump 11 a small amount of fluid tends to cling to an outer surface 44 of pump 11. A deflector 45 is provided on pump 11 to return this extraneous fluid to reservoir 18. Deflector 45 also will prevent splash fluid from being deposited about pump 11.

Satisfactory operation of oil pump 11 will continue as long as intake opening 17 is in contact with or submerged within fluid reservoir 18. Experience with pump 11 has proven that the surface 36 of reservoir 18 can be varied from intake opening '17 to a point on outer surface 44 which very nearly coincides with deflector 45 and the pump Will sustain satisfactory lubricant flow. However, deep submersion of intake opening 17 is not necessary for satisfactory operation of pump 11 and consequently pump 11 is very versatile under actual operating conditions. Experiments have shown once satisfactory oil flow has commenced in pump 11, the intake opening 17 of the oil pump can actually be lifted as much as A of an inch above surface 36 of fluid reservoir 18 and the oil pump will continue to draw lubricant from reservoir 18 into cavity 19 for continued lubrication. .An explanation for this phenomenon is that a partial vacuum is probably created within cavity 19, this vacuum being of sufficient magnitude to maintain a column of fluid between surface 36 and intake opening 17, thus maintaining fluid flow.

Even though surface agitation on reservoir 18 may occasionally break the physical contact between fluid surface 36 and the intake opening 17,the one piece pump 11 will continue to discharge adequate quantities of fluid for lubrication purposes since fluid 22 which exists on walls 23 of the cavity is of adequate quantity to replace the fluid discharged from pressure reservoir 21. Fluid 22 also maintains the pressure head of pressure reservoir 21 during the intervals when agitation of the surface of reservoir interrupts the fluid flow along the walls 23.

Referring now to FlG. 4 there is illustrated an alter nate embodiment of the preferred embodiment shown in FIG. 1. Passageways 37 of FIG. 4 are drilled through the body 34 of pump 38 and at an angle with respect to central axis 28. A pressure reservoir is formed at the juncture between walls 23 and 39 as was created in the embodiment shown in FIG. 1. The pressure head developed in cavity 41 forces fluid through passageways 37. An additional force, however, exists to aid the transfer of fluid from pressure reservoir 42 to discharge opening 43 through passageways 37. This added force is centrifugal force acting on the fluid within passageways 37. Since passageways 37 present a physical surface similar to wall 23 as illustrated in FIG. 3, the centrifugal forces acting upon that fluid have force vector components which are similar to the force component vectors 32 and 31. A force vector corresponding to that of vector component 32 aids in forcing fluid in passageways 37 in the upwardly direction, thus, reducing the pressure head required to move fluid from reservoir 42 to discharge opening 43.

Lip 47 is placed on pump 38' in FIG, -4 for illustrating a means for altering the fluid flow from passageways 37. The fluid discharged from passageways 43 strikes lip 47 and forms a thin film of lubricant which flows from lip 47 onto surface 48 and lubricates the meshing gear as illustrated in FIG. 1.

It is to be understood that the above-described arrangement of apparatus and components and construction of elemental parts are simply illustrative of the application of the principles of the invention, and many other modifications may be made without departing from the invention.

What is claimed is:

1. In a gear train a first gear, a second gear for driving said first gear, said second gear having a fluid pump formed on and depending from said second gear for lubricating said first and second gears, and means for rotatively driving said second gear and pump, said pump having a body with a cavity with inclined smooth unobstructed walls terminating in an opening in a fluid reservoir at one end, said body forming a wall at the other end of said cavity for entrapping lubricating fluid forced into said cavity through said opening by centrifugal forces imparted to the fluid by rotation of said pump in said reservoir of lubricating fluid, said body having a passageway of sufliciently small diameter for precluding the fluid entrapped in said cavity from freely flowing out the passageway to cent-rifugally pressurize the entrapped fluid, said passageway interconnecting a discharge opening and said cavity for conducting said pressurized entrapped fluid from said cavity to said discharge opening Where rotation of the gear imparts centrifugal forces to the fluid to radially dispense the fluid to lubricate said first and second gears.

2. In a gear train a first gear, a second gear for driving said first gear, said second gear having a fluid pump formed on and depending from said second gear for pumping lubricating fluid to said first gear, a body portion of said pump extending from a side of said second gear and having a frusto-conical cavity terminating in an intake opening at one end, said body forming an enclosing surface at the other end of said cavity, means for rotatively driving said second gear and pump to i1n part circular motion to fluid in contact with said intake opening to force fluid by centrifugal force upwardly along smooth unobstructed conical walls of the cavity to entrap the fluid between said walls and said enclosing surface of said body, said body having passageways of sufficiently small diameter for precluding the entrapped fluid from freely flowing out the passageways to centrifugally pressurize the entrapped fluid, said passage- Ways interconnecting discharge openings and said cavity for conducting said pressurized fluid from said cavity to said discharge openings where the fluid is radially dispensed to lubricate said first gear, and means extending from an outer surface of said body for directing extraneous fluid back into the fluid reservoir.

References Cited in the file of this patent UNITED STATES PATENTS 2,067,123 Hait Jan. 5, 1937 2,149,921 Lea Mar. 7, 1939 2,419,905 Miess Apr. 29, 1947 2,783,088 Butler Feb. 26, 1957 2,826,398 Norris Mar. 11, 1958 FOREIGN PATENTS 259,222 Great Britain Nov. 25, 1926 

1. IN A GEAR TRAIN A FIRST GEAR, A SECOND GEAR FOR DRIVING SAID FIRST GEAR, SAID SECOND GEAR HAVING A FLUID PUMP FORMED ON AND DEPENDING FROM SAID SECOND GEAR FOR LUBRICATING SAID FIRST AND SECOND GEARS, AND MEANS FOR ROTATIVELY DRIVING SAID SECOND GEAR AND PUMP, SAID PUMP HAVING A BODY WITH A CAVITY WITH INCLINED SMOOTH UNOBSTRUCTED WALLS TERMINATING IN AN OPENING IN A FLUID RESERVOIR AT ONE END, SAID BODY FORMING A WALL AT THE OTHER END OF SAID CAVITY FOR ENTRAPPING LUBRICATING FLUID FORCED INTO SAID CAVITY THROUGH SAID OPENING BY CENTRIFUGAL FORCES IMPARTED TO THE FLUID BY ROTATION OF SAID PUMP IN SAID RESERVOIR OF LUBRICATING FLUID, SAID BODY HAVING A PASSAGEWAY OF SUFFICIENTLY SMALL DIAMETER FOR PRECLUDING THE FLUID ENTRAPPED IN SAID CAVITY FROM FREELY FLOWING OUT THE PASSAGEWAY TO CENTRIFUGALLY PRESSURIZE THE ENTRAPPED FLUID, SAID PASSAGEWAY INTERCONNECTING A DISCHARGE OPENING AND SAID CAVITY FOR CONDUCTING SAID PRESSURIZED ENTRAPPED FLUID FROM SAID CAVITY TO SAID DISCHARGE OPENING WHERE ROTATION OF THE GEAR IMPARTS CENTRIFUGAL FORCES TO THE FLUID TO RADIALLY DISPENSE THE FLUID TO LUBRICATE SAID FIRST AND SECOND GEARS. 